EWSR1 and Ewing sarcoma: Although overall FISH testing was more reliable, the additional RT–PCR testing was useful in identifying a fusion transcript containing an EWSR1 rearrangement in FISH-negative cases, particularly for Ewing sarcoma (four cases, 3.6%), DRSCT (two cases, 9.1%), AFH (four cases, 20.0%), CCSLGT (one case, 20.0%) and LGFMS and SEF (six cases, 31.6%).